EKG: What It Can And Can’t Do

The EKG machine remains a singularly elegant piece of medical technology. A few electrodes are placed on the patient’s skin, a few twists of the controls, and the clinician has a representation of the electrical activity of the heart. But like every piece of technology, the EKG machine has its strengths and its limitations. Here, a quick review of what an EKG can, and can’t, do.

Using an EKG machine, a trained clinician can determine the following.

• Evidence of damage to different parts of the muscle of the heart, either from a prior myocardial infarction or one that is currently developing
• Evidence of impaired or blocked blood flow to the muscle of the heart, useful in diagnosing unstable angina or a myocardial infarction
• Tachycardia, bradycardia, or irregular heart beat
• Evidence of hypertrophy of the muscle of the heart
• Evidence of some congenital heart abnormalities
• Evidence of myocarditis or pericarditis
• How the heart is oriented in the chest cavity
• Rate and rhythm of the heart’s muscular contractions
• Patterns of atypical or abnormal electrical activity, possibly from underlying cardiac disorders
• Damage to the heart from chronic disease including hypertension, emphysema, etc.

With all that an EKG machine can do, it is sometimes difficult to remember its limitations. First among these limitations is that the EKG is a picture of cardiac activity only at the moment the EKG is taken. Some underlying heart problems can be severe and yet not show any symptoms on a routine EKG. For example, a patient with severe coronary artery disease may be asymptomatic and have a normal EKG under routine testing. Only an EKG recorded during a stress test can give an accurate picture of this type of condition.

But the greatest risk with the use of EKG is that by some patients, it is considered the ultimate measure of heart health. Not all cardiac conditions can be discovered during a routine EKG. In the patient with heart symptoms or a familial history of heart disease, additional cardiac testing is required for a thorough assessment.

Technorati Tags: ekg machine, EKG Machines, medical equipment